Matricaria
Matricaria L.
(excl. Tripleurospermum Schultz-Bip.)
Matricaria is a genus of six or seven species native to Eurasia, North America and North Africa (but several have become more or less cosmopolitan weeds). One species, Matricaria chamomilla L. (syn.: M. recutita L.), is native (or at least archaeophytic) in Belgium.
Tripleurospermum (with two native species: T. inodorum (L.) Schultz-Bip. and T. maritimum (L.) Koch) is traditionally placed within Matricaria (see also Lambinon & al. 2004). However, molecular research showed that it is in fact more closely related to Anthemis than to Matricaria (Oberprieler 2001). Morphologically, both genera are easily distinguished on achene characters: Tripleurospermum has 3-ribbed achenes with two distinct resin sacs whereas in Matricaria achenes are 5-ribbed without resin sacs. Also, as a rule, Matricaria is aromatic and Tripleurospermum scentless.
1 Heads discoid. Tubular florets usually 4-lobed, greenish yellow. Achenes 1-1,5 mm long === Matricaria discoidea
Heads radiate. Tubular florets 5-lobed, yellow to greenish yellow. Achenes 0,75-0,9 mm long (native) === M. chamomilla
Additional alien: Matricaria chamomilla var. coronata J. Gay ex Boiss. (Medit., wool alien).
Literature:
Applequist W.L. (2002) A reassessment of the nomenclature of Matricaria L. and Tripleurospermum Sch. Bip. (Asteraceae). Taxon 51(4): 757-761.
Brouillet L. (2006) Matricaria. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 19. Oxford University Press, New York-Oxford: 540-542.
Djavadi S.B., Naqinezhad A. & Ramezankhah S. (2007) Matricaria discoidea, a new species of the Asteraceae - Anthemideae for the flora of Iran. Rostaniha 8(2): 106-107.
Heath P.V. (1994) Commentary on the proposal to conserve Matricaria Linné. Calyx 4: 48-50.
Hoste I. (2006) Matricaria discoidea. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 576-577.
Jeffrey C. (1979) Note on the lectotypification of the names Cacalia L., Matricaria L. and Gnaphalium L. Taxon 28: 349-351.
Kay Q. & Hutchinson G. (1993) The truth about Pineapple Weed? BSBI News 63: 51.
Lambinon J., Delvosalle L., Duvigneaud J. (avec coll. Geerinck D., Lebeau J., Schumacker R. & Vannerom H.) (2004) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Cinquième édition. Jardin botanique national de Belgique, Meise: CXXX + 1167 p.
Mitsuoka S. & Ehrendorfer F. (1972) Cytogenetics and evolution of Matricaria and related genera. Österr. Bot. Z. 120: 155-200.
Oberprieler C. (2001) Phylogenetic relationships in Anthemis L. (Compositae, Anthemideae) based on nrDNA ITS sequence variation. Taxon 50: 745-762.
Rauschert S. (1974) Nomenklatorische Probleme in der Gattung Matricaria L. Folia Geobot. Phytotax. 9: 249-260.
Sell P. & Murrell G. (2006) Flora of Great Britain and Ireland. Vol. 4 Campanulaceae – Asteraceae. Cambridge University Press, Cambridge: XXVIII + 624 p.
Skilbeck C.A., Lynch I., Ellenby M. & Spencer M.A. (2019) Achene Morphology of British and Irish Mayweeds and Chamomiles: implications for taxonomy and identification. British & Irish Botany 1(2): 128-166. [available online at: https://britishandirishbotany.org/index.php/bib/article/view/16/30]